在SWIFT中使用NSDictionary填充UITable

时间：2017-02-25 00:12:53

标签： swift uitableview nsdictionary

我有一个从JSON请求中检索的字典，我想用这些值填充表。我认为一切都还可以，但是我在Type SubjectsViewController does not conform to protocol 'UITableViewDataSource'我正在使用故事板的类声明中收到错误，并且我在UI上将表格视图添加到datasource和delegate以及据我所知，我正在正确实现这些功能。我在下面添加了代码的相关部分。

查看this这可能是有用的，这是我发布的问题，以了解我使用回调的原因。提前谢谢！

class SubjectsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

  override func viewDidLoad() {
        super.viewDidLoad()

        getSubjects(callback: {(resultValue)-> Void in

            func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
                return resultValue.count
            }

            func tableView(_ tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
                let cell = UITableViewCell(style: UITableViewCellStyle.default, reuseIdentifier: "cell")
                cell.textLabel?.text = resultValue[indexPath.row] as! String?
                return cell
            }

        })
    }

    // Initialise components of the view
    let UserDetails = UserDefaults.standard.stringArray(forKey: "UserDetailsArray") ?? [String]()
    @IBOutlet weak var tableView: UITableView!

    // Function to retrieve the subjects for the user
    func getSubjects(callback: @escaping (NSDictionary)-> Void){

        let myUrl = NSURL(string: "www.mydomain.com/retrieveSubjects.php");
        let request = NSMutableURLRequest(url:myUrl as! URL)
        let user_id = UserDetails[0]
        request.httpMethod = "POST";
        let postString = "user_id=\(user_id)";
        request.httpBody = postString.data(using: String.Encoding.utf8);

        let task = URLSession.shared.dataTask(with: request as URLRequest){
            data, response, error in

            if error != nil {
                print("error=\(error)")
                return
            }

            var err: NSError?
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
                if let parseJSON = json {
                    let resultValue: NSDictionary = parseJSON["subjects"] as! NSDictionary
                    callback(resultValue)
                }
            } catch let error as NSError {
                err = error
                print(err!);
            }
        }
        task.resume();
    }
}

编辑：在解包可选值时，CLASS意外发现nil 

class SubjectsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

var dataDict: [String:AnyObject]?
@IBOutlet var tableView: UITableView!
let userDetails: [String] = UserDefaults.standard.stringArray(forKey:"UserDetailsArray")!

override func viewDidLoad() {
    super.viewDidLoad()
    self.dataDict = [String:AnyObject]()
    self.tableView.delegate = self
    self.tableView.dataSource = self
    self.getSubjects()
}

func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.dataDict!.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell(style: UITableViewCellStyle.value1, reuseIdentifier: "cell")
    let array = self.dataDict?[String(indexPath.row)] as! [String]

    print(array)

    cell.textLabel?.text = array[0]
    cell.detailTextLabel?.text = array[1]
    return cell
}

func getSubjects() {

    let myUrl = NSURL(string: "www.mydomain/retrieveSubjects.php");
    let request = NSMutableURLRequest(url:myUrl as! URL)
    let user_id = userDetails[0]
    request.httpMethod = "POST";
    let postString = "user_id=\(user_id)";
    request.httpBody = postString.data(using: String.Encoding.utf8);

    let task = URLSession.shared.dataTask(with: request as URLRequest) {
        data, response, error in

        if error != nil {
            print("error=\(error)")
            return
        }

        var err: NSError?
        do {
            let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
            if let parseJSON = json {
                let resultValue = parseJSON["subjects"] as! [String:AnyObject]
                self.dataDict = resultValue
                self.tableView.reloadData()
            }
        } catch let error as NSError {
            err = error
            print(err!);
        }
    }
    task.resume();
}
}

2 个答案:

答案 0 :(得分：2)

以下是您需要做的事情：

首先，为您的数据创建一个类变量。把它放在你的班级声明之下：

var dataDict: [String:AnyObject]?

然后，为了保持组织有序，将tableView属性和userDetails属性直接放在dataDict下。

@IBOutlet var tableView: UITableView!
let userDetails: [String] = UserDefaults.standard.stringArray(forKey:"UserDetailsArray")

现在，您的viewDidLoad方法应如下所示：

override func viewDidLoad() {
    super.viewDidLoad()
    self.dataDict = [String:AnyObject]()
    self.tableView.delegate = self
    self.tableView.dataSource = self
    self.getSubjects()
}

在此之下，您需要处理UITableViewDataSource方法：

func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.dataDict.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = UITableViewCell(style: UITableViewCellStyle.value1, reuseIdentifier: "cell")
    if let array = self.dataDict[String(indexPath.row)] as? [String] {
        cell.textLabel?.text = array[0]
        cell.detailTextLabel?.text = array[1]
    }
    return cell
}

最后，您需要实施getSubjects()方法：

func getSubjects() {

    let myUrl = NSURL(string: "www.mydomain.com/retrieveSubjects.php");
    let request = NSMutableURLRequest(url:myUrl as! URL)
    let user_id = UserDetails[0]
    request.httpMethod = "POST";
    let postString = "user_id=\(user_id)";
    request.httpBody = postString.data(using: String.Encoding.utf8);

    let task = URLSession.shared.dataTask(with: request as URLRequest) {
        data, response, error in

        if error != nil {
            print("error=\(error)")
            return
        }

        var err: NSError?
        do {
            let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
            if let parseJSON = json {
                let resultValue = parseJSON["subjects"] as! [String:AnyObject]
                self.dataDict = resultValue
                self.tableView.reloadData()
            }
        } catch let error as NSError {
            err = error
            print(err!);
        }
    }
    task.resume();
}

总而言之，您的代码应如下所示：

class SubjectsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    var dataDict: [String:AnyObject]?
    @IBOutlet var tableView: UITableView!
    let userDetails: [String] = UserDefaults.standard.stringArray(forKey:"UserDetailsArray")

    override func viewDidLoad() {
        super.viewDidLoad()
        self.dataDict = [String:AnyObject]()
        self.tableView.delegate = self
        self.tableView.dataSource = self
        self.getSubjects()
    }

    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.dataDict.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell(style: UITableViewCellStyle.value1, reuseIdentifier: "cell")
        if let array = self.dataDict[String(indexPath.row)] as? [String] {
            cell.textLabel?.text = array[0]
            cell.detailTextLabel?.text = array[1]
        }
        return cell
    }

    func getSubjects() {

        let myUrl = NSURL(string: "www.mydomain.com/retrieveSubjects.php");
        let request = NSMutableURLRequest(url:myUrl as! URL)
        let user_id = UserDetails[0]
        request.httpMethod = "POST";
        let postString = "user_id=\(user_id)";
        request.httpBody = postString.data(using: String.Encoding.utf8);

        let task = URLSession.shared.dataTask(with: request as URLRequest) {
            data, response, error in

            if error != nil {
                print("error=\(error)")
                return
            }

            var err: NSError?
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary
                if let parseJSON = json {
                    let resultValue = parseJSON["subjects"] as! [String:AnyObject]
                    self.dataDict = resultValue
                    self.tableView.reloadData()
                }
            } catch let error as NSError {
                err = error
                print(err!);
            }
        }
        task.resume();
    }
}

答案 1 :(得分：1)

以下是您班级的最小结构：

class SubjectsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { /* ... */ }
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { /* ... */ }
}

如果它看起来不像，那就不符合UITableViewDataSource，也不会编译。如果它不能用作UITableViewDataSource，那么您的表将不会显示任何单元格。

相关问题
最新问题